1. Technical Field
This invention relates to an art of controlling access to document data and in particular to an art of controlling access using electronic paper for holding display of a document image in a no-power supply state.
2. Related Art
Electronic data in various media such as an image and text is handled using a computer and a document is created, edited, read, etc.
To read such an electronic document, generally a document image is displayed on a display screen of a computer, or a document image is printed on paper of a paper medium using a printer.
In recent years, paper-like flexible thin electronic paper capable of holding display of an image in a no-power supply state has been developed as a document read medium that can replace paper.
The electronic paper is a device having a display for holding display of an information image in a no-power supply state and is roughly classified into self-write type electronic paper having a function of writing an image to the display for itself based on electronic data and transfer write type electronic paper for holding an image written by projection transfer, thermal transfer, etc., on the display according to the write manner of an information image to the display.
Unlike paper, such electronic paper enable to erase or overwrite the image whose display is held on the display and can be used repeatedly and therefore it is also desirable to promote the user of the electronic paper from the viewpoint of paper resource savings, etc.
Generally, document data is stored in storage of a database, etc., for management and the storage inhibits any other user from accessing document data without permission of the owner user.
Therefore, for any other user to access any desired document data, he or she needs to obtain permission of access from the owner user of the document data.
To permit a different user to access the document data, the owner user of the document data gives identification information of the document data, identification information of the different user, information of permitted processing description (read, edit, etc.,) to the storage for setting the access right by manual input using an input machine of a keyboard, a mouse, etc., and this work is cumbersome for the owner user. Setting the access right by manual input causes a setting mistake of granting the access right to document data different from the intended document data or granting the access right to a user different from the intended user, for example.
It is therefore an object of the invention to make it possible to grant the access right to document data easily and as intended by using electronic paper.